Whilst 1-30 can take several months for some people, they still need sharding at launch purely to prevent dead servers emerging once the launch period is over.
I'd rather live with sharding momentarily to ensure my server isn't a desolate waste finding myself having to re-roll onto a new server.
The WoW Classic panel was absolutely great, and I'm confident that all of the decisions they've made are for good reason, whether it's sharding, Rogue energy ticks or mail limitations. All are exactly what I would've done given the choice.

BfA has probably been my favourite expansion since WotLK (TBC and WotLK were my favourites purely because that's when I was most invested).
Currently sat at ilvl 323 and going to attempt some mythics over the weekend in preparation for the PvP season starting at the start of September. I need to find way more haste gear to stack.

Everywhere should scale now, so you can actually complete the story of a zone without it feeling completely pointless because you outleveled it.
I haven't leveled from 1 in a while so can't answer the latter though. I'm going to unlock the Zandalari Allied Race before I decide to do 1-110 so I can get some heritage armour.

Have you had the quest active at the time of learning new words?
I've had it happen with Supply Depots and Crashed Freighters where it hasn't noticed I've actually done what has asked because I had a different quest selected. Bit of a long shot, but worth asking.

There's a pre-event going on at the minute (you pick it up from Sylvanas in UC) which if you complete rewards you with an Undercity Plaguebat:
Not sure about mods really either, I've had the same UI since forever.

If you need to level any other alts, keep an eye out for the legion invasions. They give an insane amount of experience for very little effort.
I just pop across to my alts whenever I see them rather than actively questing. So much easier to do now that I'm effectively on a PvE server too. Being Horde on Sylvanas with the 85% Alliance player base was painful without stealth.

I think it's 150u for the teleporter. If you open up your inventory, it should say that the teleporter is enabled (if you're between 50 - 150 units of your ship) in red text.
Anything beyond 150 and it'll say it's disabled.